Podocytopathy and Glomerular Basement Membrane Anomalies in Two Patients With Cubilin Gene Mutations

Proteinuria is a frequent finding in pediatric patients and in most cases, it is intermittent or transient. When proteinuria is moderate/severe and persistent, it may require an extensive complementary study, histopathological examination and genetic test, in order to clarify its etiology. Cubilin (CUBN) is a large glycosylated extracellular protein, initially detected in proximal tubular cells, and later in podocytes. Isolated persistent proteinuria caused by cubilin gene mutations is rare, only a few cases have been reported in the literature and even fewer patients underwent renal biopsy and electron microscopy that could help to elucidate the pathogenesis of the disease. The authors describe two pediatric clinical cases referred to pediatric nephrology consultation due to persistent proteinuria. Neither of them had any other complaints, and renal function and immunological and serological studies were normal. Renal histopathology showed podocytes changes and glomerular basal membrane alterations suggestive of Alport Syndrome. The genetic study identified two heterozygous variants in the cubilin gene in both, also later identified in their parents. They were started on ramipril, with improvement in proteinuria, and both patients remain asymptomatic and without changes in renal function. At present, due to the uncertainty of prognosis, it is suggested to keep CUBN gene mutation patients under close surveillance of proteinuria and renal function. The variable ultrastructural patterns of podocytopathy and glomerular basal membrane alterations in kidney biopsies of pediatric patients with proteinuria should lead to the diagnostic possibility of CUBN gene mutation in the differential diagnosis.

Cerebral venous thrombosis in adolescence: Looking beyond the obvious

Behçet's disease (BD) is a rare systemic vasculitis with multisystemic involvement. Neurological involvement, called neuro-Behçet's disease (NBD), mostly involves the central nervous system and cerebral venous thrombosis (CVT) is the predominant neurological manifestation in the pediatric age. A 12-year-old female with a past medical history of a CVT, without an identifiable etiology, was admitted with a five-day right fronto-orbital headache. Neuroimage showed a subacute thrombosis of a right superficial sylvian vein, with indirect signs of intracranial hypertension and no imaging signs of vasculitis. Prothrombotic screening and immunologic study were normal. She was started on acetazolamide and hypocoagulation with progressively improving. She had a history of frequent oral aphthae and an episode of a genital ulcer three months before admission. Pathergy test was negative. HLA-B51 was positive. She was diagnosed with NBD and started therapy with colchicine and infliximab. After discharge, the patient remains without symptoms, hypocoagulated, and on infliximab regimen, without complications to report. This case, only diagnosed in the second episode of CVT, is paradigmatic of the difficulty in establishing the diagnosis of BD.

Neonatal Atypical Hemolytic Uremic Syndrome in the Eculizumab Era

The atypical hemolytic uremic syndrome (aHUS) in the newborn is a rare disease, with high morbidity. Eculizumab, considered a first-line drug in older children, is not approved in neonates and in children weighing less than 5 kg. We present a 5-day-old female newborn, born at 36 weeks' twin gestation, by emergency cesarean section due to cord prolapse, with birth weight of 2,035 g and Apgar score of 7/7/7, who develops microangiopathic hemolytic anemia, thrombocytopenia, and progressive acute renal failure. In day 5, after diagnosis of aHUS, a daily infusion of fresh frozen plasma begins, with improvement of thrombocytopenia and very slight improvement in renal function. The etiologic study (congenital infection, Shiga toxin, ADAMTS13 activity, directed metabolic study) was normal. C3c was slightly decreased. On day 16 for maintenance of anemia and severe renal failure, she started 300 mg/dose eculizumab. Anemia resolves in 10 weeks and creatinine has normal values after 13 weeks of treatment. The genetic study was normal. In this case, eculizumab is effective in controlling microangiopathy and in the recovery of renal function. Diagnosis of neonatal aHUS can be challenging because of phenotypic heterogeneity and potential overlap with other manifestations that may confound it, such as perinatal asphyxia or sepsis/disseminated intravascular coagulation.

2016 update of the Portuguese recommendations for the use of biological therapies in children and adolescents with Juvenile Idiopathic Arthritis

OBJECTIVE

To provide evidence-based guidance for the rational and safe prescription of biological therapies in children and adolescents with juvenile idiopathic arthritis (JIAs) considering the latest available evidence and the new licensed biologics.

METHODS

Rheumatologists and Pediatricians with expertise in Pediatric Rheumatology updated the recommendations endorsed by the Portuguese Society of Rheumatology and the Portuguese Society of Pediatrics based on published evidence and expert opinion. The level of agreement with final propositions was voted using an online survey.

RESULTS

In total, 20 recommendations to guide the use of biological therapy in children and adolescents with JIAs are issued, comprising 4 general principles and 16 specific recommendations. A consensus was achieved regarding the eligibility and response criteria, maintenance of biological therapy, and procedures in case of non-response, for each JIA category. Specific recommendations concerning safety procedures were also updated.

CONCLUSIONS

These recommendations take into account the specificities of each JIA category and are intended to continuously improve the management of JIA patients.